On Tue, Jun 01, 2010 at 08:50:02PM -0700, Arve Hjønnevåg wrote:> On Tue, Jun 1, 2010 at 7:05 AM, mark gross <640e9920@gmail.com> wrote:> > On Tue, Jun 01, 2010 at 09:07:37AM +0200, Florian Mickler wrote:> ...> >> +static void update_target_val(int pm_qos_class, s32 val)> >> +{> >> + s32 extreme_value;> >> + s32 new_value;> >> + extreme_value = atomic_read(&pm_qos_array[pm_qos_class]->target_value);> >> + new_value = pm_qos_array[pm_qos_class]->comparitor(val,extreme_value);> >> + if (extreme_value != new_value)> >> + atomic_set(&pm_qos_array[pm_qos_class]->target_value,new_value);> >> +}> >> +> >> > Only works 1/2 the time, but I like the idea!> > It fails to get the righ answer when constraints are reduced. But, this> > idea is a good improvement i'll roll into the next pm_qos update!> >> > I think it would be a better idea to track your constraints with a> sorted data structure. That way you can to better than O(n) for both> directions. If you have a lot of constraints with the same value, it> may even be worthwhile to have a two stage structure where for> instance you use a rbtree for the unique values and list for identical> constraints.

I don't agree, we went through this tree vrs list discussion a few timesbefore in other areas of the kernel. Wherever the list tended to beshort, a simple list wins. However; we can try it, after we have somemetrics and stress test cases identified we can measure its effectivenesagainst.